photosynthesis-related stress on plants and their...

Seminar Nasional Pemanfaatan Bioteknologi untuk Mengatasi Cekaman Abiotik pada Tanaman

68

Photosynthesis-related Stress on Plants and Their Resistance to It

Masaaki Takahashi Laboratory of Plant Molecular Biology, Department of Applied Life Sciences

Graduate School of Life and Environmental Sciences, Osaka Prefecture University

Chlorophyll Itself was Gained as a Light Guard

Solar Energy is Used to Drive Creative or Non-creative Reactions in

Oxygenic Photosynthetic Organisms

Chl and Protein

in 80% Et-OH

Light

Heat

Energy transfer

*Chl

Chl-protein complex

in water

Chl and Protein

in 80% Et-OH

Chl-protein complex

in water


69

Reactive Oxygen Species (ROS); Unavoidable Gifts from Oxygenic Photosynthetic World

Oxygen Metabolism in the Chloroplast

H2O

PSII

3O2

1O2

Glycollate-2-P

OH-

Catalase

Catalase

SOD

*Chl

Fenton catalysts

RuBisCO

hv Scavengers

PSI hv

O2- H2O2

SOD

OH-


70

Photorespiration Protects C3 Plants from Photooxidation Akiko Kozaki and Go Takeba Nature 384: 557-560 (1996)

Photorespiratory Pathway

Glycerate-3-P

O2

RuBP CO2 O2

Glycerate-3-P

Glycollate-2-P

glycollate

glycollate glyoxylate

glycine

glycine serine

serine

hydroxypyvuvate glycerate glycerate ATP

glutamate

2-oxo- glutarate glutamine

ATP

CO2 NADH

NADH

NH3 NH3

NADH glutamate

2-oxo- glutarate

O2

glutamate

Chloroplast Peroxisome

Mitochondrion

GS2


71

Photorespiration (CO2 Burst) Highly Depends on Glutamine Synthetase (GS2) Activity

∆CO2/min

CO2 conc. L D


72

NH3 Accumulates in Chloroplasts when CO2 Flow is Shut Down

GS2 Transgenic Plant is Not Photoinhibited

0.75 mM


73

GS2 Transgenic Plant is Not Photoinhibited

C4 Photosynthesis was Evolved ~70 Million Years Ago to Cope with Recent Climate Changes by Dissipating Solar Energy Once Absorbed

HCO3-

PEP(C3) Pyr

ATP Pi

OAA(C4) Mal Mal(C4)

Pyr(C3)

CO2

RuBP(C5)

PGA (C3)

NADH

C4ppdk

AMP PPi

RuBisCO

NAD(P)H

Mesophyll cell Bundle sheath cell

PEPCase

Control GS2 transgenic


74

Recent Evolution of Chloroplast-type Isoform from Cytosolic Pyruvate Pi Dikinase J. Sheen Plant Cell 3:225-245 (1991)

M A P A P C G R S S Q R V F H F G K G KA TGGCGCCCGCTCCATGTGGCCGTTCGTCGCAGAGGGTGTTCCACTTCGGCAAGGGCAAG

ACCACCAAAAAGAGGGTGTTCCACTTCGGCAAGGGCAAGT T K K R V F H F G K G K

S E G N K N M K E L L G G K G A N L A EA GCGAGGGCAACAAGAACATGAAGGAGCTGCTGGGCGGCAAGGGCGCGAACCTGGCGGAGA GCGAGGGCAACAAGACCATGAAGGAGCTGCTGGGCGGCAAGGGCGCGAACCTGGCGGAG

S E G N K T M K E L L G G K G A N L A E

M A S I G L S V P P G F T V S T E A C QA TGGCGAGCATCGGGCTGTCGGTGCCGCCGGGGTTCACGGTGTCGACGGAGGCGTGCCAGA TGGCGAGCATCGGGCTGTCGGTGCCGCCGGGGTTCACGGTGTCGACGGAGGCGTGCCAG

M A S I G L S V P P G F T V S T E A C Q

Q Y Q E A G R A L P P G L W A E V L D GC AGTACCAGGAGGCCGGGCGCGCCCTCCCGCCGGGGCTCTGGGCGGAGGTCCTCGACGGCC AGTACCAGGACGCCGGGTGCGCCCTCCCC GCGGGGCTCTGGGCCGAGATCGTCGACGGC

Q Y Q D A G C A L P A G L W A E I V D G

L R W V E E Y M G AC TGCGGTGGGTGGAGGAGTACATGGGCGCCC TGCAGTGGGTGGAGGAGTACATGGGCGCC

L Q W V E E Y M G A

cyppdkZm1 Promoter

TATAAA CAGGCCC ATGGCGCCCGCTCCATGTGGCCGTTCGTCGCAGAGGM A P A P C G R S S Q R

C4ppdkZm1 Promoter cyppdkZm1 Promoter

GT / / TATAAA CAGGCCC ATGGCGCCCGTTCAATGTGCGCGT - - - TCGCAGAGGTTKK M A P V Q C A R S Q R

ATG C4ppdkZm1 intron1transit peptide


75

Nitrate Assimilation by Plant − The Role of the Nitrite Transporters (CsNitr1-L&-S) −

Uptake of NO2, NO, and CO2 by the Nitrite Transporter (CsNitr1-S) Transgenic Arabidopsis

NO3- NO3

-

NO2- S NO2

- NH4+

Amino acids

6Fd+ 6Fd2+

PApo- plast

Chloroplast

Vascular cell

Soil solution

L

S4-1 line

S1-3 line

Wild type CO2 NO

NO2

％

0

20

40

60

80

100

120

140

160

180


76

NO2 Assimilation by the Nitrite Transporter (CsNitr1-S) Transgenic Plant

Path for the Atmospheric CO2 and NO2 to Plant Cells

Spongy mesophyll Palisade mesophyll

NO2 NO2

NO2- NO2

- NO2- NO2

-

NO3-

NO3-

NO3-

NO2- condensation in the

apoplast

NO

S S

L

nH+

Lower epidermis

Spongy mesophyll

Palisade mesophyll

Upper epidermis

Stomata

CO2 NO2

Vacu-ole

Chloroplast


77

Phenotypic Difference of Nitrite Transporter (CsNitr1-S) Transgenic Arabidopsis from Its Control (Col-0)

Laboratory of Plant Molecular Biology (Ex-Laboratory of Soil and Plant Biosciences)

Masaaki Takahashi

Miwa Sugiura

Sustiprijatno

Mihaela N. Georgescu

Grant A. Griffith

WT

S1 line

WT S1 line

photosynthesis-related stress on plants and their...

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